Modified D-value method to predict seismic strength of multi-story steel moment resisting frames with mid-story pin column base system

The D-value method a simple method to predict stoay drift distribution of a moment-resisting frame under lateral forces. This paper evaluates elasto-plastic behavior of a steel moment-resisting frame adopting a mid-story pin column base system, which has been inoducedtopreventcolumn bases from yielding. The proposed modified D-value method successful predict moment and story drift distributions of the low -to-mid story frames with mid-story picolumn base system. By the D-value method, it is shown that flexural demand on columns exceed twice as large as the full-plastic moment of beams for 6- and 9-story frame.